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Biomedical subjects

K Caidahl

Publications and source records attributed to K Caidahl.

At least 109 records · Page 6Linked to original sources
PubMed1994

Atrial natriuretic peptide and its relation to cardiac dimensions and function in patients with systemic sclerosis.

OBJECTIVES: Were to determine whether plasma atrial natriuretic peptide (ANP) is increased in patients with systemic sclerosis (SScl) and to evaluate its relation to cardiac dimensions and function. METHODS: Using radio-immunoassay, plasma ANP was determined in 30 patients with SScl and 48 age and sex matched controls. The plasma ANP level was related to cardiac structure and function as determined by two-dimensional echocardiography (2-D echo). RESULTS: Plasma ANP was markedly elevated among patients as compared to controls (239,4 +/- 59 vs 178.2 +/- 36 pmpl/l, p < 0.0005). The left atrial long-axis and area were increased, and ANP was directly related to both measurements (r = 0.27, p < 0.05 and r = 0.40, p < 0.005, respectively). Plasma ANP was also related to the increased right atrial long-axis (r = 0.27, p < 0.05). The ANP level was not related to LV systolic function as estimated by ejection fraction, fractional area change and end-systolic wall stress, neither did these measures differ between patients and controls. However, there was an inverse correlation between ANP level and stroke volume (r = -0.35, p < 0.05), which was lower among the patients (p < 0.005). ANP displayed also an inverse relation to LV long axis diameter (r = -0.37, p < 0.005) and area (r = -0.42, p < 0.005) as well as to LV end-diastolic volume (r = -0.42, p < 0.005). Various measurements indicated LV hypertrophy among the SScl patients in spite of a small LV cavity. ANP was directly related to measures of LV hypertrophy, as interventricular septum thickness (r = 0.44, p < 0.005), LV posterior wall thickness (r = 0.34, p < 0.05), the wall thickness to cavity dimension ratio (r = 0.36, p < 0.05), and LV myocardial area (r = 0.36, p < 0.05). There was no relationship between ANP concentration and heart rate, blood pressure or total peripheral resistance. CONCLUSION: These results suggest that the ANP production is not reduced in SScl. Rather, circulating ANP is elevated in relation to the degree of LV hypertrophy. This implies that ANP may be useful for the identification of cardiac involvement in patients with SScl.

Adult↗
PubMed1994

Atrial natriuretic peptide: relation to left ventricular filling properties in patients with systemic sclerosis.

To determine the relation between left ventricular filling properties and plasma atrial natriuretic peptide in systemic sclerosis, we evaluated 30 consecutive patients and 48 age- and sex-matched controls. The venous plasma atrial natriuretic peptide was measured by radio-immunoassay. Left ventricular involvement was evaluated by echocardiography and mitral regurgitation was evaluated by Doppler. The patient group had markedly elevated plasma atrial natriuretic peptide as compared to the matched controls, (239.4 +/- 59 vs. 178.2 +/- 36 pmol/l, P < 0.0005). We found signs of impaired left ventricular filling properties among the patients with an increase of the Doppler A-wave velocity and A/E ratio. A relative reduction of early filling was found in spite of some degree of mitral regurgitation in two-thirds of the patients. The plasma atrial natriuretic peptide concentration was related to the A-wave velocity (r = 0.44, P < 0.0005), the A/E ratio (r = 0.40, P < 0.005), and also to the degree of mitral regurgitation (r = 0.43, P < 0.005). The relationship to the A-wave velocity remained when considering possible confounding factors. We conclude that the previously observed fibrotic process in systemic sclerosis does not prevent production and liberation of plasma atrial natriuretic peptide in relation to factors distending the left atrium, such as altered left ventricular filling properties and the presence of mitral regurgitation. However, the moderate relationships between atrial natriuretic peptide and haemodynamic variables indicate that the peptide might also be an independent indicator of cardiac involvement in systemic sclerosis.

Adult↗
PubMed1994

Cardiovascular and renal effects of growth hormone.

OBJECTIVE: With the advent of recombinant human GH (rhGH), it has become possible in controlled clinical studies to explore the effects of GH replacement in adults with GH deficiency. The objective of this study was to determine cardiovascular and renal effects of GH replacement in adults with GH deficiency. PATIENTS: We studied ten patients (one woman and nine men), mean age 47 years, with GH deficiency. DESIGN: The patients were given s.c. rhGH (Humatrope, Eli Lilly) 0.5 U/kg/week or placebo in a 6-month double blind cross-over study. Cardiac and renal function was measured before drug administration (baseline), before cross-over (i.e. after 6 months), and before termination of drug administration (after another 6 months). Analysis of variance was used to compare measurements during GH replacement with baseline and placebo measurements. One patient was excluded because of atrial fibrillation. MEASUREMENTS: Main outcome measures were glomerular filtration rate and Doppler-echocardiographic estimates of cardiac function and structure. Computerized exercise electrocardiogram, spirometry, and blood samples for analyses of plasma hormones were also obtained. RESULTS: Left ventricular function was maintained during GH replacement. However, left ventricular mass increased from 211 to 249 g (P < 0.05) mainly due to increased left ventricular dimension since wall thicknesses did not increase. The left atrium increased from 38 to 41 mm (P < 0.05), possibly because stroke volume increased from 92 to 118 ml (P < 0.0001) and cardiac output increased from 5.29 to 7.58 l/min (P < 0.05). Total peripheral resistance decreased from 18.9 to 12.4 mmHg min/l (P < 0.05), and diastolic blood pressure from 79 to 72 mmHg (P < 0.05). Heart rate at rest increased from 58 to 70 beats/min. Systolic blood pressure at rest was unchanged, as was systolic blood pressure during dynamic exercise. GH replacement did not cause ST-abnormalities. Serum creatinine decreased from 91.4 to 85.3 mumol/l (P < 0.05) and glomerular filtration rate increased from 89.6 to 99.8 ml/min (P < 0.01). CONCLUSIONS: Thus, GH replacement has favourable cardiovascular and renal effects including increase of stroke volume and glomerular filtration rate with reduction of peripheral resistance.

Adult↗
PubMed1994

Recovery from left ventricular asynergy in ischemic cardiomyopathy following long-term beta blockade treatment.

It has been suggested that long-term beta blockade treatment in congestive heart failure might be less effective in patients with ischemic cardiomyopathy as compared with patients having idiopathic dilated cardiomyopathy. This study was performed to evaluate the effect of long-term adrenergic beta blockade treatment on regional myocardial function in patients with ischemic cardiomyopathy. The regional wall motion (RWM) was evaluated in 12 patients with ischemic cardiomyopathy before and after long-term open treatment with metoprolol. On average, the patients were treated over 11 months (range 6-36 months). The regional left ventricular function was assessed using two-dimensional echocardiographic recordings by two independent blinded observers. The RWM score was evaluated in 16 segments of the left ventricle on a scale from 0 (hypercontractility) to 5 (dyskinesia). Following treatment, there was an improvement in general ventricular function (ejection fraction 0.24-0.31; p = 0.01) as well as in RWM (86 improved segments, 48 deteriorated, 49 unchanged; p < 0.002). Ventricular segments with poor contractility (RWM score > or = 3.5) tended to improve (53 improved segments, 16 deteriorated, 13 unchanged; p < 0.0001), whereas less severely impaired segments (RWM score < 3.5) did not improve (33 improved segments, 32 deteriorated, 36 unchanged; NS). It is suggested that poorly contracting myocardial segments might improve following beta blockade treatment, while an effect on less impaired segments might be lacking. An improvement in overall myocardial function would then be harder to detect.

Aged↗
PubMed1994

Renovascular resistance in primary hypertension: experimental variations detected by means of Doppler ultrasound.

OBJECTIVE: To gauge the influence of renovascular resistance changes on blood flow velocity pulsatility in kidneys of hypertensive patients by means of the ultrasonic colour and pulsed-wave Doppler method, since we have previously shown in normotensive subjects that the blood flow velocity pulsatility in renal interlobar arteries varies with changes in renovascular resistance. METHODS: In six male patients with primary hypertension, renal blood flow velocity profiles were investigated by means of duplex ultrasound. Single-kidney renovascular resistance was assessed by measurements of split renal function (gamma-camera renography), renal plasma flow (steady-state para-aminohippurate clearance) and cuff blood pressure. The pulsatility index of the blood flow velocity spectrum in the renal interlobar artery and renovascular resistance were measured either at rest, during infusion of angiotensin II, or after angiotensin converting enzyme inhibition. RESULTS: A significant correlation existed between pulsatility index and renovascular resistance (r = 0.50, P < 0.002), which did not improve after correction for the blood pressure pulsatility. Changes of pulsatility index were more closely related (r = 0.64, P < 0.001) to the corresponding changes in renovascular resistance. CONCLUSIONS: With the two-dimensional image-guided colour and pulsed-wave Doppler method it is possible to assess semiquantitatively small intra-individual changes in renovascular resistance in hypertensive patients by means of pulsatility index measurements. Pharmacologically induced alterations in renovascular haemodynamics may therefore be evaluated with this technique.

Angiotensin II↗
PubMed1994

10-year experience with the Biocor porcine bioprosthesis in the aortic position.

Six hundred and nineteen consecutive patients had aortic valve replacement between January 1983 and January 1993 with the zero pressure fixed Biocor porcine bioprosthesis. Mean age was 66.2 years (range 17-88 years). Male/female ratio was 416/203. Concomitant cardiac procedures, mainly coronary bypass surgery, were performed in 35% (214/619). Early mortality was 5.9% (37/619). Late mortality was 15.8% (92/582). Actuarial survival at 10 years was 60.0 +/- 4.9% and freedom from valve-related mortality was 97.6 +/- 0.8%. Total follow up was 2308 years. The follow up was 99.2% complete. Thromboembolic rate was 1.1%/pty (fatal 0.1%/pty, major 0.3%/pty and minor 0.6%/pty). The incidence of prosthetic valve endocarditis was 0.3%/pty (fatal 0.1%/pty). Freedom from reoperation due to structural valve deterioration, non-structural dysfunction and prosthetic valve endocarditis was 78.1 +/- 10.7%, 98.5 +/- 0.6% and 97.6 +/- 0.9%, respectively. The occurrence of structural valve deterioration varied considerably between age groups. In patients below 50 years of age the actuarial freedom from structural valve deterioration was 52.4 +/- 22.0%, while it was 96.2 +/- 1.1% for those between 71 and 80 years. At the 10-year follow up all patients had improved clinically. Preoperatively, 75% of the patients were in NYHA classes III or IV compared to 8% at the 10-year follow up. We conclude, that the Biocor bioprosthesis has a low rate of complications in terms of thromboembolism, anticoagulant-related bleeding, prosthetic valve endocarditis and valve-related mortality as compared to mechanical valves and also to other bioprostheses. The durability of the Biocor bioprosthesis has increased slightly compared to that reported with other, earlier models when inserted in patients above 50 years of age.

Actuarial Analysis↗
PubMed1993

Attenuation of left ventricular dilatation after acute myocardial infarction by early initiation of enalapril therapy. CONSENSUS II Multi-Echo Study Group.

This trial investigated the effect of enalapril, administered early, on left ventricular (LV) volumes after myocardial infarction. Four hundred twenty-eight patients included in the Cooperative New Scandinavian Enalapril Survival Study (CONSENSUS II) were examined with echocardiography within 5 days, at 1 month and at 6 months after myocardial infarction. Enalaprilat (1 mg) or placebo infusion was initiated within 24 hours after infarction, followed by oral treatment to a target dose of 20 mg/day. A significant attenuation of LV dilatation was noted at 1 month in patients treated with enalapril compared with those receiving placebo. Changes in LV end-diastolic volume indexes during the first month were (mean +/- SEM) 5.7 +/- 1.0 ml/m2 for the placebo group and 1.9 +/- 0.8 ml/m2 for the enalapril group (p < 0.02). Changes in LV end-systolic volume indexes were 3.1 +/- 0.8 and 0.5 +/- 0.6 ml/m2, respectively (p < 0.02). The between-group difference was most marked in patients with anterior wall infarction (p < 0.005). Volume changes beyond the first month were similar in both groups but the differences observed at 1 month were maintained. The larger volumes in the placebo versus enalapril group were significant or borderline significant at 1 and 6 months. Thus, enalapril treatment initiated early after myocardial infarction and continued for 6 months can attenuate LV dilatation during the first month resulting in smaller LV volumes after 1 and 6 months.

Aged↗
PubMed1992

Tricuspid valve insufficiency as a complication of endomyocardial biopsy.

The purpose of this study was to investigate the occurrence of major tricuspid insufficiency caused by endomyocardial biopsy in heart transplant recipients. Endomyocardial biopsy was used for the detection of rejection and Doppler echocardiography was performed at regular intervals. Six of 96 heart transplant patients (6.3%) had sudden appearance of large tricuspid regurgitation, all of which were directly related to a preceding biopsy. Chordal tissue was identified histologically in biopsy samples of all six patients. All patients developed symptoms of right ventricular failure which was confirmed by right heart catheterization. Three patients subsequently underwent valvuloplasty for ruptured chordae tendineae of either of the three leaflets. Two of these three patients were free from symptoms during follow-up, but the third patient developed moderate tricuspid regurgitation and clinical symptoms. It is concluded that endomyocardial biopsy, although it is the most useful tool for detection of rejection, should be used with caution with regard to anatomical structures and the risk of damage to the tricuspid valve must not be neglected. It is also concluded that valvuloplasty of the tricuspid valve can be successfully performed in a transplanted heart.

Adolescent↗
PubMed1992

Experimental variations in renovascular resistance in normal man as detected by means of ultrasound.

The pulsatility index (PI) of blood flow velocities has been reported to vary with changes in peripheral vascular resistance. Since blood flow velocities can easily be detected with the Echo-Color-Doppler technique in interlobar arteries of normally positioned kidneys, we tried in six healthy volunteers to estimate pharmacological induced variations in renal plasma flow (RPF) and renovascular resistance (RVR) by means of PI measurements. In this study no significant correlation between the absolute values of PI and RVR was found. In order to correct PI for different blood pressure-inputs to the renal artery, PI was divided by the pulsatility of the systemic arterial pressure, i.e. the 'blood pressure index' [BPI = (SAD-DAP)/MAP)], resulting in the 'velocity blood-pressure index' (VBI = PI/BPI), which was significantly correlated with RVR (r = 0.54, P less than 0.01). The pharmacological induced changes of RPF and RVR (delta RPF, delta RVR) were also correlated to the respective changes of PI and VBI (delta PI, delta VBI), with the highest significance when delta VBI was plotted against delta RVR (r = 0.83, P less than 0.0001). VBI, i.e. the pulsatility index of blood flow velocities as corrected for the pulsatility of the driving force, may be a tool for noninvasive assessment of changes in RVR and thereby of importance for the diagnosis and follow-up of renovascular diseases.

Adult↗
PubMed1992

Effects of surgical stress and volatile anesthetics on left ventricular global and regional function in patients with coronary artery disease. Evaluation by computer-assisted two-dimensional quantitative transesophageal echocardiography.

We investigated the effects of halothane, enflurane, and isoflurane on central hemodynamics and left ventricular global and regional function when used to control intraoperative hypertension in 39 patients with coronary artery disease. Left ventricular short-axis, midpapillary images were obtained by transesophageal echocardiography. Using a centerline algorithm, we analyzed left ventricular images for global area ejection fraction (GAEF) and segmental area ejection fraction (SAEF). The SAEF/GAEF ratio was calculated for each of eight segments. Measurements were performed after induction of anesthesia but before skin incision; 1 min after sternotomy; and during administration of the inhaled anesthetic. The increase in arterial blood pressure during sternotomy was due to an increase in vascular resistance accompanied by increases in heart rate and filling pressures while GAEF decreased. No changes in the SAEF/GAEF ratio appeared during sternotomy. The inhaled anesthetics restored arterial blood pressure by a similar decrease in vascular resistance. Isoflurane caused an increase in cardiac index that was not seen with halothane or enflurane (halothane vs isoflurane, P < 0.05). The GAEF was decreased by halothane but unaffected by isoflurane and enflurane (halothane vs enflurane; P < 0.05). Isoflurane induced a decrease in the SAEF/GAEF ratios of two segments corresponding to the inferolateral wall of the left ventricle that was, in one of these segments, significantly more pronounced compared with both halothane and enflurane. Halothane or enflurane did not cause any change in regional wall motion. We conclude that isoflurane is more likely to cause regional wall motion changes than halothane or enflurane in patients with coronary artery disease.

Adult↗
PubMed1991

Non-invasive assessment of systolic left ventricular function in systemic sclerosis.

Systemic sclerosis is a multisystemic disorder, also affecting the heart. To evaluate its influence on systolic left ventricular (LV) function, we investigated 30 consecutive patients (age 54.5 +/- 2.4 years, 15 men and 15 women) and 48 controls matched for age and sex. All subjects were investigated by phonocardiography, pulse curve recordings, M-mode echocardiography, and by pulsed and continuous wave Doppler. Heart rate, blood pressure and peripheral resistance did not differ, but patients weighed less than controls (P less than 0.01). Systolic time intervals indicated systolic impairment, with an increased pre-ejection period to LV ejection time (LVET) ratio (0.37 +/- 0.02 vs 0.30 +/- 0.01 P less than 0.001), and also an increased isovolumic contraction time to LVET ratio (0.17 +/- 0.02 vs 0.12 +/- 0.01, P less than 0.02). The latter difference remained when LVET was adjusted for heart rate. Echocardiographic E-point to septal separation was increased in patients (8.3 +/- 1.3 vs 4.8 +/- 0.3 mm, P = 0.001), also after adjustment for LV dimension (P = 0.0001), while septal fractional thickening was decreased (P less than 0.01). End systolic wall stress (P = 0.0002) and stress to volume ratio (P = 0.03) were lower in systemic sclerosis. Peak LV emptying rate was also lower in the patient group when measured by echocardiography (P = 0.03). There was no difference between groups regarding LV dimensions, fractional shortening or mean velocity of circumferential fibre shortening. While aortic Doppler peak emptying rate did not differ between groups, it occurred later in systole in the patient group (P less than 0.01) as did peak velocity (P = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Non-invasive evaluation of long-term cardiac effects of captopril in systemic sclerosis.

Impairment of left ventricular (LV) function has previously been reported in patients with systemic sclerosis (SScl). An intermittent vasospastic process in the myocardium may contribute to the development of myocardial dysfunction. Vasodilators may therefore be potentially useful in the treatment of cardiac dysfunction in patients with SScl. This study was designed to evaluate the long-term effects of captopril on the myocardial function of patients with SScl. Twenty-two patients with SScl (15 patients with diffuse scleroderma and 7 patients with CREST syndrome, i.e. calcinosis. Raynaud's phenomenon, oesophageal hypomotility, sclerodactyly, telangiectasia) were investigated by means of Doppler and echophonocardiography before and after treatment with captopril (1.3 mg kg-1 body weight d-1) for 11-15 months. There were no significant differences in heart rate, systolic and diastolic blood pressure, end-systolic blood pressure, total peripheral resistance or LV diameters before or after treatment. However, captopril treatment exerted significant effects on LV function: the pre-ejection period (PEP) and the ratio of pre-ejection period to LV ejection time decreased significantly (P less than 0.05). Mitral E-point septal separation decreased significantly (P less than 0.01), even after adjustment for LV end-diastolic diameter (P less than 0.01). The ejection fraction increased significantly (P less than 0.05), and the isovolumic relaxation time decreased (P less than 0.01). The left atrial emptying index increased (P less than 0.01). The Doppler peak late to early ventricular filling velocity decreased (P less than 0.05), and the isovolumic index was also reduced (P less than 0.05). We conclude that both systolic and diastolic LV function indices improved in patients with SScl after captopril treatment for a mean period of 1 year. The effects of captopril might be due to vasodilation of the myocardial vessels and/or a direct effect on the renin-angiotensin system of the heart.

Adult↗
PubMed1991

Adenosine infusion to patients with ischaemic heart disease may provoke left ventricular dysfunction detected by echocardiography.

Infusion of the endogenous vasodilator adenosine to patients with ischaemic heart disease (IHD) frequently provokes myocardial ischaemia, possibly caused by a coronary steal. The aim of this study was to detect the occurrence and incidence of disturbances in left ventricular (LV) wall motion and Doppler indices of altered LV function during infusion of adenosine. Thirty-seven patients (six female) aged 37-74 years with IHD, verified by coronary angiography, were given up to 200 micrograms kg-1 min-1 (mean 155 +/- 5) adenosine i.v. for 18 +/- 1 min. LV wall motion was monitored by two-dimensional echocardiography (2D-echo). Doppler spectral signal was obtained from the mitral blood flow. All but six of the patients experienced angina pectoris of habitual character in connection with the adenosine infusion. Heart rate increased by 22 +/- 1 beats min-1, systolic blood pressure was unchanged, but diastolic blood pressure decreased slightly. 2D-echo revealed severe regional LV wall motion disturbances already in the basal state in 17 patients. During infusion of adenosine, these abnormalities were aggravated and disturbances also occurred in another 15 patients. Thus, adenosine increased the sensitivity for IHD in this selected material from 49 to 89%. In all, the mean index of wall motion abnormalities increased from 5.1 +/- 1.1 to 10.1 +/- 1.4 (P less than 0.001). The diastolic LV filling characteristics, as evaluated by the Doppler A/E ratios, were of limited value for determination of IHD grade. It is concluded that infusion of adenosine to patients with IHD frequently elicits myocardial ischaemia with disturbances in LV function, and offers an alternative to exercise for stress echocardiography.

Adenosine↗
PubMed1991

Management of disseminated midgut carcinoid tumours.

Forty-one patients with disseminated midgut carcinoid tumours were treated over a 6-year period according to a strict programme including primary surgical treatment. In 10 patients, a total remission of the disease was obtained. Patients with bilobar hepatic disease had ischaemic treatment of their liver metastases by hepatic arterial embolisation after primary surgical and medical treatment (low dose octreotide). Thus, by combining surgical, radiological and medical treatment modalities, we wanted to offer these patients optimal palliation. This treatment programme resulted in good symptomatic relief in all patients accompanied by a marked reduction in 5-hydroxyindoleacetic acid (5-HIAA) levels. At recurrence of symptoms in combination with rising 5-HIAA levels, embolisation was repeated. Ten of the treated patients have deceased during the observation period, but only 5 from their carcinoid disease.

Adult↗
PubMed1991

Epidemiology and prognosis of heart failure.

Congestive heart failure (CHF) is a major cause of mortality and morbidity, and has a prognosis similar to that of several malignancies. There are increasing trends in both prevalence and incidence rates of CHF which points towards CHF becoming a major community health problem. Early detection of CHF is dependent upon criteria to define the initial stages of a condition which progresses slowly over many years. In western countries the dominant causes of CHF are hypertension and coronary heart disease, which account for more than 75% of the cases. Other precursors are diabetes and rheumatic heart disease. Independent risk factors for CHF are hypertension, smoking, obesity, and psychological stress. Early detection of CHF through identification of early symptoms such as dyspnea on exertion, treatment of known heart diseases, and treatment of risk factors may prevent its progress. Epidemiological data indicate that primary preventive efforts should be directed against hypertension, smoking and obesity. A multiple risk factor interventional approach seems to yield the best result since these risk factors act synergistically.

Cause of Death↗
PubMed1990

Mitral regurgitation and diastolic flow profile in systemic sclerosis.

To evaluate the left ventricular filling characteristics in systemic sclerosis, we examined 30 consecutive patients, 15 men and 15 women, and related the findings to those from 48 age- and sex-matched controls. All patients were investigated by pulsed and continuous wave mitral Doppler, and M mode echocardiography. We found the A wave of the mitral flow velocity as recorded by pulsed wave Doppler to be higher in patients (0.74 +/- 0.07 vs 0.54 +/- 0.02 m/sec, P less than 0.002), while the E wave did not differ. The high A/E ratio indicating reduced distensibility, correlated to interventricular septal thickness (r = 0.53, P less than 0.001), and atrial emptying index (r = -0.55, P less than 0.001). Early filling was impaired, with a prolonged pressure half time (99 +/- 6 vs 84 +/- 4 msec, P less than 0.05), and a reduced first third filling fraction (0.41 +/- 0.02 vs 0.48 +/- 0.01, P less than 0.001). Mitral regurgitation was found in 67% of systemic sclerosis patients and in 15% of controls (P less than 0.001). Doppler measures of left ventricular filling properties were not related to the presence of mitral regurgitation or systolic blood pressure. We conclude that left ventricular distensibility and early filling properties are impaired in systemic sclerosis and not related to blood pressure, but rather to left ventricular wall thickness and therefore probably secondary to myocardial fibrosis. Mitral regurgitation is a common finding in systemic sclerosis.

Adult↗
PubMed1990

Non-invasive assessment of the cardiovascular eicosanoids, thromboxane A2 and prostacyclin, in randomly sampled males, with special reference to the influence of inheritance and environmental factors.

1. We studied, in a random sample of 385 nonsmoking men born in 1968-1969 and 31 men born in 1913 or 1923, whether inheritance and environmental factors influenced platelet activity and vessel wall prostacyclin formation, as reflected non-invasively by the urinary excretion of the 2,3-dinor-metabolites of thromboxane A2 (2,3-dinor-thromboxane B2, Tx-M) and prostacyclin (2,3-dinor-6-keto-prostaglandin F1 alpha, PGI-M), respectively. 2. Fathers of young men with high platelet activity did not excrete more Tx-M than fathers of young men with low platelet activity. Men born in 1913 or 1923 displayed higher Tx-M (563 versus 128 pg/mg of creatinine, P less than 0.001) and PGI-M (163 versus 130 pg/mg of creatinine, P less than 0.01) excretion than those born in 1968-1969. Excretion of both Tx-M and PGI-M was correlated to the urinary output of noradrenaline and adrenaline. 3. Well-trained subjects did not differ in their excretion of Tx-M or PGI-M from those who did not exercise regularly. A recent acute infection was also unrelated to the excretion of Tx-M or PGI-M. PGI-M excretion was, however, significantly correlated to Tx-M excretion (r = 0.51, P less than 0.001). 4. This study provides the first non-invasive evidence that advancing age and sympathoadrenal tone are positively correlated to platelet activity in randomly sampled men, and that paternal inheritance, physical fitness and recent infection lack correlation to platelet activity.

6-Ketoprostaglandin F1 alpha↗